How Old Is Your Water Heater? Reading the Label

Where it is

Look on the side of the tank, usually near the top or beside the gas valve or electrical cover. A flashlight helps in a dark basement.

Decoding the date

The manufacture date is usually built into the serial number. Many brands use a letter for the month and two digits for the year. Searching the brand with "serial number date" will show the pattern.

Gallons and recovery

The tank size in gallons shows how much hot water it stores. The first-hour rating, if shown, tells you how much it can deliver in a busy hour.

Gas or electric

Gas models list BTU input; electric models list voltage and element wattage. A replacement needs to match, or the plumber will explain what has to change.

What the age means

Many tanks last around eight to twelve years. Past that, leaks and failures get more likely, so plan a replacement rather than waiting for a cold shower.

Next step

Send the label details with your request. See water heaters.

Winter makes it work harder

In a Missoula winter the water coming into the tank is much colder, so the heater runs longer to reach the same temperature. A tank that just about kept up in summer may run short in January. If that happens every winter, the next heater may need a bigger capacity or a better first-hour rating.

Keep a note

Write the brand, model, size and date on a piece of tape on the tank.

More plumbing guides

• Keeping Pipes Thawed Through a Missoula Winter
• What to Do When a Pipe Bursts
• Checking for a Hidden Leak
• Closing Up a Cabin or Empty House for Winter
• Hiring a Licensed Plumber in Montana